The medium and heavy duty vehicle markets have traditionally used two types of maintenance practices for maintaining vehicle electrical systems. One method is to provide corrective maintenance when a failure occurs. For example, on-board electronic systems perform electrical system checks and create active faults for the driver or maintenance technician.
The second method is to provide preventive vehicle maintenance on a predefined schedule of mileage intervals or of operational or time intervals. The preventive maintenance is scheduled before a fault occurs. Repair, replacement of components, or cleaning of electrical terminals “re-sets” the vehicle system back to like-new conditions. This approach is an attempt to preempt road breakdowns and the interrupts of normal operation when a failure occurs. While this procedure may work at keeping a vehicle in service, it does have a higher cost because in general more maintenance is performed than what is required.
The industry is now embracing the concept of Condition Based Maintenance (CBM). CBM is the optimal-level of vehicle maintenance, and performed at the proper time. CBM utilizes real-time data to prioritize and optimize maintenance resources. Such a system can determine the equipment's health, and act only when maintenance is necessary.
However, CBM is not utilized for major electrical components, such as batteries (usually two or more in parallel), starters, alternators, and supporting hardware including cables and wiring. Instead, preventive maintenance are used for diagnoses. Industry standards, such as TMC RP129 “Heavy Duty Vehicle Cranking and Starting Troubleshooting” and TMC RP132 “Battery Charging, Testing and Handling” describe the procedures to follow for proper diagnoses.
RP129 is a maintenance procedure performed by a technician with off-board test equipment. First, the batteries are charged and evaluated. Then a special automated (electronic) tester or carbon pile resistor is used to load down the circuit so high amperage can be drawn from the battery. The technician ensures the prescribed current is maintained while the voltages are recorded. This allows for the voltage dropped across the circuit(s) be measured directly or calculated based on other measurements taken. By using an assortment of tests, the battery, cranking circuit, and charging circuit are diagnosed.
However, the existing CBM techniques may still require off-board testing, which may be impractical under certain circumstances. The disclosed methods and systems are directed to solve one or more problems set forth above and other problems.